A132138 Characteristic function of the set of numbers defined in A002977.

1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset: 1

Author

Reinhard Zumkeller, Aug 20 2007

Keywords

• nonn

Comments

a(A002977(n)) = 1 and a(A132142(n)) = 0.

Links

• R. Zumkeller, Table of n, a(n) for n = 1..10000
• Index entries for characteristic functions

Formula

a(n) = if chi(n) then 1 else 0, where chi(n) = if n<3 then (n=1) else ((n mod 2 = 1) AND chi((n-1)/2)) OR ((n mod 3 = 1) AND chi((n-1)/3)).